2-mercapto-4,6-dichloro-s-triazines and their substituent products are known intermediate products in the production of herbicides.
They are produced by starting with cyanuric chloride and reacting it with a mercaptan in the presence of an organic base or alkali compound such as soda lye, sodium carbonate or sodium bicarbonate or corresponding alkaline earth compounds as hydrogen chloride acceptors. (W. F. Beech, J. Chem. Soc., London, 1967 (c), page 470 et seq. The entire disclosure of the Beech article is hereby incorporated by reference and relied upon.)
According to another process as set forth in German Pat. No. 1670585 (the entire disclosure of which is hereby incorporated by reference and relied upon) the mercaptotriazines mentioned are obtained in very pure form and in high yields directly by carrying out the reaction in a heterogenous system which consists of water and at least one water immiscible organic solvent inert to cyanuric chloride. The temperature used was below the boiling point of the solvent.
Now it would be desirable to have a process in which the substituted 2-mercapto-4,6-dichloro-s-triazines are producible continuously in the reactor with high purity.
Through the very short residence time of the reactants in the reactor the by-products are reduced substantially and the yield and purity increased.